未来气候变化对淮河流域径流的可能影响

采用新安江月分布式水文模型,结合1961—2000年历史月气候资料和4个CGCMs的3个SRES排放情景下(B1,A2,A1B)未来降水和气温情景模拟结果,对过去淮河流域的径流进行模拟检验并对未来2011—2040年的径流影响进行评估,为水资源管理和规划提供依据。结果表明:水文模型能较好地反映年、月流量以及多年平均值和季节的变化;年流量模拟一般好于月流量,淮河干流主要控制水文站如王家坝、鲁台子、蚌埠的年流量模型效率系数均在80以上;多年平均值模拟效果好,平均绝对相对误差为10。多数CGCMs不同排放情景下气候模拟结果表明:未来2011—2040年,淮河流域气候将趋于暖湿,但年径流量将可能以减少趋势为主。这对淮河地区水资源的可持续发展以及东线调水工程水资源统一调配和管理提出了较大的挑战。淮河流域大部分区域2011—2040年月径流量减少将主要发生在1月和7—12月,变化趋势较为确定;4—6月,径流量将以增加趋势为主,不确定性较大;2—3月,径流具有增加趋势的地区多分布在淮河以北地区,具有减少趋势的地区则多分布在淮河干流及以南地区和洪泽湖、平原区,这些地区增加或减少趋势的不确定性较大。

1951—2006年三峡库区夏季气候特征

以重庆市的沙坪坝、涪陵、万州、奉节和湖北省的宜昌5个站为代表,从降水、气温、日照、风速和蒸发等5个要素系统地分析了三峡库区1951—2006年夏季的气候变化特征。结果表明:三峡库区夏季降水量总体呈增加趋势,特别是在20世纪70年代末发生了一次明显跃变;最高气温、平均气温、日照时数以及蒸发量等总体呈下降趋势,在20世纪80年代初发生了一次明显跃变;平均最低气温和平均风速的变化趋势不明显,但所有气候要素均表现出明显的年代际变化特征。

Temporal-Spatial Structure of Intraplate Uplift in the Qinghai-Tibet Plateau

The intraplate uplift of the Qinghai-Tibet Plateau took place on the basis of breakup and assembly of the Precambrian supercontinent, and southward ocean-continent transition of the Proto-, Paleo-, Meso- and Neo-Tethys during the Caledonian, Indosinian, Yanshanian and Early Himalayan movements. The intraplate tectonic evolution of the Qinghai-Tibet Plateau underwent the early stage of intraplate orogeny characterized by migrational tectonic uplift, horizontal movement and geological processes during 180-7 Ma, and the late stage of isostatic mountain building characterized by pulsative rapid uplift, vertical movement and geographical processes since 3.6 Ma. The spatial-temporal evolution of the intraplate orogeny within the Qinghai-Tibet Plateau shows a regular transition from the northern part through the central part to the southern part during 180-120 Ma, 65-35 Ma, and 25-7 Ma respectively, with extensive intraplate faulting, folding, block movement, magmatism and metallogenesis. Simultaneous intraplate orogeny and basin formation resulted from crustal rheological stratification and basin-orogen coupling that was induced by lateral viscous flow in the lower crust. This continental dynamic process was controlled by lateral flow of hot and soft materials within the lower crust because of slab dehydration and melted mantle upwelling above the subducted plates during the southward Tethyan ocean-continent transition processes or asthenosphere diapirism. Intraplate orogeny and basin formation were irrelevant to plate collision. The Qinghai-Tibet Plateau as a whole was actually formed by the isostatic mountain building processes since 3.6 Ma that were characterized by crust-scale vertical movement, and integral rapid uplift of the plateau, accompanied by isostatic subsidence of peripheral basins and depressions, and great changes in topography and environment. A series of pulsative mountain building events, associated with gravity equilibrium and isostatic adjustment of crustal materials, at 3.6 Ma, 2.5 Ma, 1.8-1.2 Ma, 0.9-0.8 Ma and 0.15-0.12 Ma led to the formation of a composite orogenic belt by unifying the originally relatively independent Himalayas, Gangdise, Tanghla, Longmenshan, Kunlun, Altyn Tagh, and Qilian mountains, and the formation of the complete Qinghai-Tibet Plateau with a unified mountain root after Miocene uplift of the plateau as a whole.

Stochastic modeling of daily precipitation in China

A stochastic model for daily precipitation simulation in China was developedbased on the framework of a 'Richardson-type' weather generator that is an important tool instudying impacts of weather/climate on a variety of systems including ecosystem and risk assessment.The purpose of this work is to develop a weather generator for applications in China. The focus ison precipitation simulation since determination of other weather variables such as temperature isdependent on precipitation simulation. A framework of first order Markov Chain with GammaDistribution for daily precipitation is adopted in this work. Based on this framework, fourparameters of precipitation simulation for each month at 672 stations all over China were determinedusing daily precipitation data from 1961 to 2000. Compared with previous works, our estimation forthe parameters was made for more stations and longer observations, which makes the weather generatormore applicable and reliable. Spatial distributions of the four parameters are analyzed in aregional climate context. The seasonal variations of these parameters at five stations representingregional differences are discussed. Based on the estimated monthly parameters at 672 stations, dailyprecipitations for any period can be simulated. A 30-year simulation was made and compared withobservations during 1971-2000 in terms of annual and monthly statistics. The results aresatisfactory, which demonstrates the usefulness of the weather generator.

A GIS-based Spatial Analysis of Housing Price and Road Density in Proximity to Urban Lakes in Wuhan City, China

As one of the essential urban open spaces, lakes usually contribute immensely to the quality of residents′ daily lives. Different from hedonic approach employed in existing researches on urban open spaces in China, this paper integrates housing price surface with road density to analyze the spatial characteristics in proximity to urban lakes in Wuhan City, China. With the expansion of Wuhan City, urban lakes became polluted, they shrunk or even disappeared, leading to unfavorable conditions for sustainable development of the city. To better understand the spatial relationship between the city and lakes, we classify the urban lakes in Wuhan central area into ′lakes in the urban center′ and ′lakes in urban fringe′. Based on housing price surface we explore the spatial characteristics in proximity to different lakes and differences between the lakes. We also use Geographic Information System(GIS) tool to calculate road density as a supplementary indicator to reflect the accessibility in proximity to urban lakes. The results indicate that relative independence exists between different towns, and the spatial characteristics are different depending on scales and locations. In most of cases, the road density is lower where closer to the lakeshore while the housing price exhibits an opposite pattern. We conclude that city governments and urban planners should give more considerations to these spatial differences, somewhere should be better planned and protected as an important waterfront and somewhere the control of unreasonable real estate development nearby should be strengthened.

Detection of Internal Leaf Structure Deterioration Using a New Spectral Ratio Index in the Near-Infrared Shoulder Region

Spectral reflectance in the near-infrared （NIR） shoulder （750-900 nm） region is affected by internal leaf structure, but it has rarely been investigated. In this study, a dehydration treatment and three paraquat herbicide applications were conducted to explore how spectral reflectance and shape in the NIR shoulder region responded to various stresses. A new spectral ratio index in the NIR shoulder region （NSRI）, defined by a simple ratio of reflectance at 890 nm to reflectance at 780 nm, was proposed for assessing leaf structure deterioration. Firstly, a wavelength-independent increase in spectral reflectance in the NIR shoulder region was observed from the mature leaves with slight dehydration. An increase in spectral slope in the NIR shoulder would be expected only when water stress developed sufficiently to cause severe leaf dehydration resulting in an alteration in cell structure. Secondly, the alteration of leaf cell structure caused by Paraquat herbicide applications resulted in a wavelength-dependent variation of spectral reflectance in the NIR shoulder region. The NSRI in the NIR shoulder region increased significantly under an herbicide application. Although the dehydration process also occurred with the herbicide injury, NSRI is more sensitive to herbicide injury than the water-related indices （water index and normalized difference water index） and normalized difference vegetation index. Finally, the sensitivity of NSRI to stripe rust in winter wheat was examined, yielding a determination coefficient of 0.61, which is more significant than normalized difference vegetation index （NDVI）, water index （WI） and normalized difference water index （NDWI）, with a determination coefficient of 0.45, 0.36 and 0.13, respectively. In this study, all experimental results demonstrated that NSRI will increase with internal leaf structure deterioration, and it is also a sensitive spectral index for herbicide injury or stripe rust in winter wheat.

Marine spatio-temporal process semantics and its applications-taking the El Nio Southern Oscilation process and Chinese rainfall anomaly as an example

Spatio-temporal semantics based on ＂object views＂ or ＂event views＂ has few abilities to represent and model the continuity and gradual oceanic phenomena or objects, which seriously limits the specific marine applications and knowledge discovery and data mining, so this paper proposes a hierarchical abstraction semantics with ＂marine spatio-temporal process-life span phases-evolution sequences--state units＂ and process objects included by level with ＂marine process objects--phase objects--sequence object---state objects＂ with the oceanic process characteristics into the marine process semantics. In addition, this paper designs the storage and representation of marine process objects using the backus normal forms （BNF） and abstract data type （ADT）. Base on E1 Nifio Southern Oscilation （ENSO） index and Chinese rain gauging station data, this paper also gives a case of study. The spatio-temporal analysis between ENSO process and Chinese rainfall anomalies shows that the marine spatio-temporal semantics not only can illustrate the spatial distribution of Chinese rainfall anomalies in different time scales at ENSO process, life span phases and state units, but also analyze the dynamic changes of Chinese rainfall anomalies in different life span phases or state units within ENSO evolution.

Recent Extremes of Drought and Flooding in Amazonia: Vulnerabilities and Human Adaptation

The present study focuses on the impacts of extreme drought and flooding situations in Amazonia, using level/discharge data from some rivers in the Amazon region as indicators of impacts. The last 10 years have featured various “once in a century” droughts and floods in the Amazon basin, which have affected human and natural systems in the region. We assess a history of such hazards based on river data, and discuss some of the observed impacts in terms of vulnerability of human and natural systems, as well as some of adaptation strategies implemented by regional and local governments to cope with them. A critical perspective of mitigation of drought and flood policies in Amazonia suggests that they have been mostly ineffective in reducing vulnerability for the majority of the population, constituting, perhaps, examples of maladaptation via the undermining of resilience.

Lightning Enhancement in the Amazon Region Due to Urban Activity

Urbanization has an increasing contribution to anthropogenic climate forcing. The impact arises mainly from the Urban Heat Island (UHI) effect and aerosol anthropogenic emissions. An important but not completely understood consequence of this forcing is its effect on local lightning activity. Changes in lightning activity may result in a feedback on the climate system. In this article, it investigates changes in the lightning activity in the city of Manaus, located in the Amazon region of Brazil. It is found that, over the city, the lightning activity is larger than in the regions around it and it has been increasing in the last four decades simultaneously with the increasing of its urban area. Our results suggest that such changes are caused by the UHI effect. The observations reported here are unique and relevant because Manaus is located in the central part of the Amazon rainforest and inside one of the three global lightning chimneys in the world.

Receiver function imaging in strongly laterally heterogeneous crust:Synthetic modeling of BOLIVAR data

We resolve a large （-20 km） discrepancy in Moho depth determined from PdS receiver functions （RFs） and from active source seismic profiling in the complex Caribbean-South American plate boundary zone in eastern Venezuela. As part of the BOLIVAR experiment 20 broadband stations were deployed along an active source profile to record teleseisms. Using the extremely heterogeneous crustal model obtained from active source data, we generated 2D finite-difference elastic wave synthetics and from them calculated receiver functions and CCP stacks. We compare the observations with synthetic sections that have been spatially sampled at 0.25 km to 40 km. The densely sampled synthetics show that several events in the field data that were originally interpreted as the Moho are multiple reflections within sedimentary basins. Where the Moho has the steepest dip under the plate boundary the CCP stacks fail to image the Moho well, regardless of the density of spatial sampling. A suitable spatial sampling criterion for clearly imaging the lower crust and Moho is to overlap Fresnel zones by 50% at Moho depth, which for the 1 Hz receiver functions examined here, requires an instrument spacing of 15-20 km, with the actual field data density ranging from 20 km to 100 km.

Sensitivity of Amazon Regional Climate to Deforestation

It is known that the Amazon region plays an important role in the global energy, hydrological cycle and carbon balance. This region has been suffering from the course of the past 40 years intense land use and land cover changes. With this in mind, this study has examined possible associations between change in spatial and temporal rainfall variability and land cover change in the Amazon, using the PRECIS regional modelling system. It has been found that the impacts of land cover change by forest removal are more intense in the so-called “Arc of deforestation” over central and southern Amazonia. However, the relative impact of the simulated rainfall changes seems to be more important in the JJA dry season. In addition, the simulations under the deforestation scenarios also show the occurrence of extreme rainfall events as well as more frequent dry periods. Therefore, the results found show to be potentially important in the modulation of regional climate variations which have several environmental and socio-economic impacts.

Characteristics of foreshock and its identi-fication

In the paper, we analyze 117 moderate-strong earthquakes occurred in Chinese mainland (Ms greater than or equal 5.5 in the east and Ms greater than or equal 6.0 in the west) since 1970, among them, 11 earthquakes (about 9%) have direct foreshocks and 63 earthquakes (about 51%) have generalized foreshocks. The predominant time interval between foreshock and main earthquake is no more than 30 days with a spatial distance less than 50 km and a magnitude difference over 1. From the digital seismic data in Liaoning Province, we know that direct foreshock had an obvious shear-stress background before the Ms=5.6 and Ms=5.1 Xiuyan earthquakes occurred on Nov. 29, 1999 and Jan.15, 2000.

Modeling the impacts of climate variability and hurricane on carbon sequestration in a coastal forested wetland in South Carolina

The impacts of hurricane disturbance and climate variability on carbon dynamics in a coastal forested wetland in South Carolina of USA were simulated using the Forest-DNDC model with a spatially explicit approach. The model was validated using the measured biomass before and after Hurricane Hugo and the biomass inventories in 2006 and 2007, showed that the Forest- DNDC model was applicable for estimating carbon dynamics with hurricane disturbance. The simulated results indicated that Hurricane Hugo in 1989 substantially influenced carbon storage immediately after the disturbance event. The simulated net ecosystem exchange (NEE) for the 58-year period (1950-2007) indicated that the hurricane reduced CO2 sequestration due primarily to the increased decomposition of a large amount of litter and woody debris, including fallen trees (over 80% of pre-hurricane trees), debris and branches, and dead roots. The inter-annual fluctuation of soil CO2 flux showed that the climate variability interfered substantially soil carbon dynamics in the forest. The results showed that there were substantial spatial and temporal differences in CO2 flux (3.2 - 4.8 Mg·C·ha–1) and wood biomass due to the differences in physical and biogeochemical characteristics in the forest.

Natural Disaster Risk in Municipal Solid Waste Disposal Sites Using GIS: A Case Study in São Paulo State, Brazil

Natural disasters and finding suitable areas to dispose of municipal solid waste (MSW) are two major global challenges, both of which have several influences in the water resources and are related to climatic change, especially in developing countries like Brazil. Currently the risk of natural disasters is not utilized in the process of locating areas to dispose of MSW. This study, using geographic information system (GIS), analyzed spatially the susceptibility for landslide and flooding hazards in MSW disposal sites in S?o Paulo state, Brazil. The results showed that more than 90% of sanitary and ditch landfills are located in null, very low and low hazard classes (P0, P1 and P2). However, in this remaining 10% of landfills we still have approximately 55% of the total municipal solid waste disposed into susceptible areas with middle, high and very high hazard classes (P3, P4 and P5). This shows that S?o Paulo MSW disposal sites need more attention and control to prevent the occurrence of landslide/flooding and consequently the mitigation of environmental, economic and social impacts. In addition, the use of GIS is proved to be an appropriate tool to carry out this type of analysis, so we recommend that the risk of natural disasters should be taken into consideration in the process of finding landfill areas. Mainly, because, there is a tendency for extreme weather events to increase causing more flood and landslide events and consequently contributing to water scarcity and water degradation.

Modeling Environmental Susceptibility of Municipal Solid Waste Disposal Sites: A Case Study in São Paulo State, Brazil

The large excess of solid waste generated in cities is a result of population growth and economic development. Properly managing this municipal solid waste (MSW) is a challenge, mainly in underdeveloped and developing countries where financial concerns are an added problem. From the environmental point of view, a major issue is properly disposing MSW taking into consideration a wide range of factors, and working with different spatial data. In this study, we used geographic information system (GIS) to perform multi-criteria decision analysis (MCDA) conducted by analytical hierarchy process (AHP). The development of the environmental impact susceptibility model (EISM) for municipal solid waste disposal sites (MSWDS) applied to the state of Sao Paulo, Brazil considered factors such as geology, pedology, geomorphology, water resources, and climate represented by fifteen associated sub-factors. The results indicated that more than 82% of Sao Paulo’s territory is situated in areas with very low, low, and medium environmental impact susceptibility categories. However, in the remaining 18% of the state land area, 85 landfills are located in areas with high and very high environmental impact susceptibility categories. These results are alarming because these 85 landfills receive approximately 17,886 tons of MSW on a daily basis, which corresponds to 46% of all municipal solid waste disposed in Sao Paulo state. Therefore, decision makers, urban planners and policymakers could use the findings of the EISM towards mitigating the environmental impacts caused by MSWDS.

Water-Energy-Food Nexus： Comparative Scenarios and Public Policy Perspectives from Some Latin American Countries Regarding Biogas from Agriculture and Livestock

Latin American and the Caribbean countries have one of the world＇s largest sources of renewable energy. Nonetheless, it estimated that nearly three-quarters of their energy consumption relies on the use of fossil fuels, with most of the countries being net importers, ultimately imposing a marked economic and political dependence on those energy commodities. Therefore, the opportunity lies in a higher utilization of various renewable energy resources, which contribute to the country＇s energy security while promoting significant environmental benefits. This manuscript aimed to provide a comparative analysis of current energy scenarios of six Latin American countries （Mexico, Honduras, Nicaragua, Brazil, Chile and Ecuador） to evaluate their policies, programs and strategies implemented in the search for greater participation of renewable energy, with a special attention to biogas. Given the importance of the water-energy-food nexus that could foment the use of renewable energies under conditions of water scarcity, a qualitative data comparison was accomplished, considering biogas production potential, biogas projects and CO2 emissions.

Mapping data gaps to estimate biomass across Brazilian Amazon forests

Background: Tropical forests play a fundamental role in the provision of diverse ecosystem services, such as biodiversity,climate and air quality regulation, freshwater provision, carbon cycling, agricultural support and culture. To understand the role of forests in the carbon balance, aboveground biomass(AGB) estimates are needed. Given the importance of Brazilian tropical forests, there is an urgent need to improve AGB estimates to support the Brazilian commitments under the United Nations Framework Convention on Climate Change(UNFCCC). Many AGB maps and datasets exist, varying in availability, scale and coverage. Thus, stakeholders, policy makers and scientists must decide which AGB product, dataset or combination of data to use for their particular goals. In this study, we assessed the gaps in the spatial AGB data across the Brazilian Amazon forests not only to orient the decision makers about the data that are currently available but also to provide a guide for future initiatives.Results: We obtained a map of the gaps in the forest AGB spatial data for the Brazilian Amazon using statistics and differences between AGB maps and a spatial multicriteria evaluation that considered the current AGB datasets. The AGB spatial data gap map represents areas with good coverage of AGB data and, consequently, the main gaps or priority areas where further biomass assessments should focus, including the northeast of Amazon State, Amapá and northeast of Pará. Additional y, by quantifying the variability in both the AGB maps and field data on multiple environmental factors,we provide valuable elements for understanding the current AGB data as a function of climate, soil, vegetation and geomorphology.Conclusions: The map of AGB data gaps could become a useful tool for policy makers and different stakeholders working on National Communications, Reducing Emissions from Deforestation and Degradation(REDD+), or carbon emissions modeling to prioritize places to implement further AGB assessments. Only 0.2% of the Amazon biome forest is sampled, and extensive effort is necessary to improve what we know about the tropical forest.

Using Geotechnology to Estimate Annual Soil Loss Rate in the Brazilian Cerrado

Soil erosion is a serious environmental problem that has adversely affected the world’s food production through the reduction of land productivity and water availability. The present study estimated annual soil loss rate and its spatial distribution in the most important Brazil’s agricultural region, the Brazilian Cerrado, using Revised Soil Loss Equation (RUSLE) model into Geographic Information System (GIS) framework. For this purpose, the soil erosion annual rate was determined in function of RUSLE model factors: rainfall erosivity (R), soil erodibility (K), topography (LS), crop management (C) and supporting conservation practice (P). All factors were obtained from literature. They were processed and integrated into a GIS, resulting in a map of annual soil loss rate. The methodology applied showed acceptable precision and it was possible to identify the most susceptible areas to water erosion. The average estimated rate of soil loss for the entire Cerrado was 12.8 t•ha−1•yr−1. Large part of the Cerrado is under low soil loss zone corresponding to 79.91% of total surface area, while 15.70%, 3.74%, and 0.66% are under moderate, high, and very high, respectively. The average estimated rate of soil loss in areas used for silviculture was 52.1 t•ha−1•yr−1. In semi-perennial, perennial, and annual crops cultivation were 29.3, 23.9, and 9.8 t•ha−1•yr−1, respectively, while in the pasture was 13.3 t•ha−1•yr−1. Except for annual crops, all farm and silviculture areas showed average soil loss ranging from moderate to high rate. These results suggest that the implementation of more effective management techniques and conservation practices are necessary for the Cerrado to maintain and to improve land productivity by ensuring national and international food demands.

An Integrated Framework to Analyze Local Decision Making and Adaptation to Sea Level Rise in Coastal Regions in Selsey (UK), Broward County (USA), and Santos (Brazil)

One of the clear signals of the ongoing climate change is sea level rise (SLR). Normal oceanic tides superimposed on a rising sea level and coastal flooding will affect many coastal communities. An international collaboration among Brazil, the United Kingdom, and the United States was designed to evaluate local decision making processes and to open space for local urban managers to reflect on possible actions toward adaption to sea level rise given the historical constraints imposed by administrative and institutional structures. This project focused on the processes that shape adaptation of three coastal communities in three countries. It worked jointly with these communities in defining the problem, examining risks, and understanding the benefits and obstacles that may hinder implementation of adaptation options. The framework was co-designed by an interdisciplinary team that incorporated social and natural scientists from the three countries, including local government officials. The study addressed 1) evaluation of adaptive capacity through participant surveys and 2) physical and cost impact simulations using geospatial models of the built infrastructure and implementation of adaptation options under different hazard scenarios, including 50 and 100-year sea level rise projections and severe storms. Based on the surveys’ results, there is a clear sense of the awareness of each community of the risk of floods due to intense storms, and of the usefulness of engaging early in a process that promotes the understanding of risks, impacts, and costs. A majority of workshop participants prioritized pursuing physical and green infrastructure actions now or within coming years or decades. A positive common aspect of the three sites was the commitment shown by the stakeholders in taking part in the process and evaluating which adaptation measures could be more effective in their cities. While in the US and UK structural solutions and voluntary buyouts were prioritized for the future, Brazil prioritized structural solutions and ecosystems restoration and not voluntary buyouts. All of these are choices to increase resiliency against sea level rise that have a high benefit-cost ratio. The Adaptive Capacity Index (ACI) results illustrate barriers to adaptation action, including technical, economic and political issues that reveal inequalities in adaptive capacity among case studies.

Sedimentary and Heavy Mineral Records for the Oligocene-Miocene Exhumation of the Easternmost Tianshan

The topography of the Harlik Mountain has a strong impact on the formation of current arid climate in the Turpan-Hami Basin.However,it is still controversial if Harlik Mountain experienced significant exhumation during the Middle to Late Cenozoic according to the previous thermochronology studies.The features of the Oligocene to Miocene sediments in the foreland basin could provide productive information for resolving the debates.The peak ages of detrital apatite fission track analysis of the Oligocene–Miocene sandstone in the Turpan-Hami Basin are well comparable with the cooling age records of the Harlik Mountain rocks,indicating that the Oligocene–Miocene Taoshuyuanzi Formation in the basin was mostly derived from the Harlik Mountain.The stratigraphic sequence exhibits coarsening upward,reflecting that the source area was in a tectonically active period during the deposition process.Heavy mineral assemblages also suggest that the unstable minerals in the sediment increased significantly at the end of the deposition.Moreover,the proportion of apatite increased up-section,while the garnet content decreased significantly,indicating that the Carboniferous metamorphic rocks have been gradually eroded out and more intrusive rocks have been exposed to the surface.These observations suggest that the Harlik Mountain experienced exhumation during the Oligocene to Miocene,and the denudation depth afterward was probably less than 2.5 km according to the previously apatite(U-Th)/He data.The Oligocene–Miocene exhumation probably acted as one of the triggers for the heavy drought of the Turpan-Hami Basin during the Middle–Late Neogene.